import java.util.Scanner;

public class Ex2_23{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		System.out.print("Enter v0, v1 and t: ");
		double v0 = input.nextDouble();
		double v1 = input.nextDouble();
		double t = input.nextDouble();
		double a = (v1 - v0) / t;
		System.out.printf("The average acceleration is %.4f\n", a);
	}
}